21340556985 has 32 divisors (see below), whose sum is σ = 37280539008. Its totient is φ = 10338168320.

The previous prime is 21340556957. The next prime is 21340556987. The reversal of 21340556985 is 58965504312.

It is not a de Polignac number, because 21340556985 - 2⁶ = 21340556921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21340556987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142639 + ... + 251051.

It is an arithmetic number, because the mean of its divisors is an integer number (1165016844).

Almost surely, 2^21340556985 is an apocalyptic number.

It is an amenable number.

21340556985 is a deficient number, since it is larger than the sum of its proper divisors (15939982023).

21340556985 is a wasteful number, since it uses less digits than its factorization.

21340556985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109625.

The product of its (nonzero) digits is 1296000, while the sum is 48.

The spelling of 21340556985 in words is "twenty-one billion, three hundred forty million, five hundred fifty-six thousand, nine hundred eighty-five".